<p>The impact of urban sprawl on house prices is not simply a promotion or suppression, which may be non-linear. This paper discusses the impact of urban sprawl on housing prices using panel data at the prefecture-level city level in China from 2003 to 2020. The research draws the following three conclusions:&#xa0;First, there is a significant U-shaped relationship between urban sprawl and housing prices, and the robustness test conclusions through methods such as instrumental variable are still reliable. Second, the mechanism analysis reveals that urban sprawl suppresses housing prices by increasing building area supply and promotes them by increasing land transfer prices. The net effect shifts from inhibitory to promotional as sprawl intensifies. Finally, urban sprawl affects house prices differently in various types of cities, with first tier cities being more affected. In addition, the promotion effect of urban sprawl on house prices is more pronounced in the eastern region, cities with small population and large area. This paper also combines the phenomenon of excessive speculation in Chinese house prices and finds that compared to before adjustment regulations, urban sprawl has a greater inhibitory effect on house prices after 2010.</p>